Arrested and tried at Dundalk, Ireland in 1679 on a charge of conspiring against the state by plotting to bring 20,000 Frenchsoldiers into the country, and for leveling a tax on his clergy to support 70,000 men for rebellion. Lord Shaftesbury knew that Oliver would never be convicted in Ireland, and had him moved to Newgate prison, London. The first grand jury found no true bill, but he was not released. The second trial was a kangaroo court; Lord Campbell, writing of the judge, Sir Francis Pemberton, called it a disgrace to himself and his country. Plunkett was found guilty of high treason “for promoting the Catholic faith,” and was condemned to a gruesome death. He was the last Catholic to die for his faith at Tyburn, London, England and the first of the Irishmartyrs to be beatified.